Complexes of

ABSTRACT

COMPLEXES SELECTED FROM THOSE REPRESENTED BY THE FORMULAS   (1) (R3P)3MB11H14   AND   (2) ((R3P)4AG)2B11H13   WHEREIN M IS EITHER COPPER OR GOLD AND EACH R IS PHENYL, (ARYL OR ALKARYL). THE COMPOUNDS ARE PREPARED BY REACTING A SALT OF B11H14- WITH A SALT OF THE METAL M IN THE PRESENCE OF THE PHOSPHINE AND IN INERT SOLVENT. THE COMPOUNDS ARE USEFUL IN DEPOSITING METAL FILMS ON SUBSTRATE SURFACES.

United States Patent 27,467 COMPLEXES OF B H AND B H Frank K. Klanberg and George W. Parshall, by E. I. du Pont de Nemours and (10., assignee N0 Drawing. Original No. 3,455,977, dated July 15, 1969, Ser. No. 601,308, Dec. 13, 1966. Application for reissue Feb. 26, 1971, Ser. No. 119,423 Int. Cl. C07f 1/10, 1/12, 1/08 U.S. Cl. 260-430 4 Claims Matter enclosed in heavy brackets II] appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE Complexes selected from those represented by the formulas wherein M is either copper or gold and each R' is phenyl. [aryl or a1karyl.] The compotmds are prepared by reacting a salt of B H with a salt of the metal M. in the presence of the phosphine and an inert solvent. The compounds are useful in depositing metal films on substrate surfaces.

This invention relates to novel metal-organic compounds. More specifically, it concerns complexes of B ll or B iH with selected metals and phosphines, and to a method for their preparation.

The novel complexes of this invention are compounds selected from those represented by the formulas wherein M is a metal selected from the group consisting of copper and gold; and each R is [of 6-12 carbon atoms selected from the class consisting of aryl and alkaryL] phenyl.

The novel complexes of this invention are prepared by reacting a soluble polyboron salt of the formula MB H wherein M is alkali metal or R,,NH wherein n is a cardinal number of 0-4 inclusive and R is lower alkyl, with a soluble salt of the metal M in the presence of the phosphine, R P, and an inert medium.

The salt of the metal M can be represented by the formulas CuX AgX, AuX and M'AuX," wherein X is one equivalent of an anion selected from the class consisting of chloride, bromide, nitrate, sulfate, formate, acetate, lactate and tartrate; X is selected from the class consisting of acetate, nitrate and fluoride, and X" is selected from the class consisting of chloride and bromide.

For convenience, the process is usually carried out at room temperatures, e.g. 20-30" C., or slightly higher temperatures, e.g., up to 50 C. The latter range is sometimes useful for effecting increased dissolution of some of the reactants. The temperature range, however, is not critical and higher or lower temperatures may be used, but present no advantage.

The R groups in the cation R,,'NH.; can be the same or different and the cations are represented by tert-butylammonium, diisopropylammonium, triethylammonium, tetramethylammonium, and the like.

Pressure is not critical and solely for convenience, atmospheric pressure is ordinarily employed.

[Nor is the ratio of reactants critical] Usually, for

optimum results, approximately stoichiometric ratios are used. As seen in the examples, the order of addition of the reactants is not critical and they can be combined in any sequence or all mixed together simultaneously.

Operable solvents include water, polar organic solvents that are at least partially miscible with water, and mixtures of the two. Examples of such polar solvents include lower alkanols such as methanol, ethanol and isopropyl alcohol; cyclic ethers such as dioxane and tetrahydro furan; open-chain polyethers such as [1,2-dimethoxymethane] 1,2-dz'methoxyethane and di(2-ethoxyethyl) ether; and lower alkanenitriles such as acetonitrile and propionitrile.

All products of the invention are relatively insoluble in the reaction medium and usually precipitate immediately when all the reactants are in mutual contact. The product can then be isolated by filtration and purified by recrystallization as shown in the examples.

The reactants CsB Hw RbB l-l (CH NHB H and (C'H NHB H can be prepared as described in Aftanclilian et al., Inorg. Chem. 1, 736 (1962). Ammonium, other alkali-metal, and other substituted ammonium B 11 salts which make up the reactants in the process of this invention are prepared from the cesium or rubidium B H salt by conventional cation exchange techniques.

[Representative phosphines (R P), both as reactants and complexed ligand groups in the compounds of the invention, include triphenylphosphine, tritolylphosphine (0-, mand p-), tris(2,5-xylyl)phosphine, tris(2,4,6-trimethylphenyl) phosphine, phenyldi-p-tolylphosphine, diphenyl-p-tolylphosphine, tris(1-naphthyl)phosphine, tris- (biphenyl)phosphine, and the like] The novel complexes of this invention are crystalline solids. Their infrared absorption spectra indicate that the metal M is bonded directly to boron of the polyboron nucleus, and is not bonded to the hydrogen of the polyboron nucleus.

The products and process of this invention are illustrated in greater detail in the following examples:

A mixture of 7.8 g. of triphenylphosphine and 1.6 g. of copper sulfate in 180 ml. of ethanol and 50 ml. of water was stirred with a solution of 3 g. of CsB H in 70 ml. of a 1:1 by volume mixture of water and ethanol. A cream-co lored solid precipitate formed which was collected and taken up in ml. of tetrahydrofuran, with warming, to yield a yellow solution. Concentration of this solution gave 5.5 g. of a solid which was separated. The product was recrystallized three times from a 1:1 by volume mixture of benzene and 1,2-dimethoxyethane to give 1 g. of [(C H P] CuB H which decomposed between 205220 C.

Analysis.-Calcd. for C H B CuP C, 66.0; H, 6.1; B, 12.1; Cu, 6.5. Found: C, 65.1; H, 6.4; B, 12.3; Cu, 6.3.

The infrared absorption (KBr wafer) showed one B-d-I absorption band at 2550 cm.- (terminal hydrogen).

Examp s s)a ]s n 14 A solution of NaAuCl -2H O (3.3 g.) in 40 ml. of ethanol was added to a mixture of triphenylphosphine (6.5 g.) and CsB H (2.6 g.) in ml. of warm ethanol and 10 ml. of water. A solid precipitated. The solid was isolated by filtration and recrystallized three times from 1,2-dimethoxyethane. The final product consisted of white crystals of [(C H P] AuB H which yellowed at C. and decomposed at 217-218 C.

Analysis.Calcd. for C H AuB P C, 58.1; H, 5.3; P, 8.3; B, 10.7; An, 17.6. Found: C, 57.7; H, 5.7; P, 7.7; B, 10.2; An, 17.1.

The infrared absorption spectrum showed one B-H absorption band at 2515 cm.- (terminal hydrogen).

Solutions of 15 g. of triphenylphosphine in 150 ml. of :thanol and 2 g. of CsB H in 20 ml. of ethanol and 20 11. of water were combined, and the resulting mixture was added with stirring to a solution of 1.7 g. of silver iitrate in 10 ml. of ethanol and 10 ml. of water. A white olid precipitated. It was separated by filtration and disolved in 100 ml. of tetrahydrofuran. When this solution Ias chilled in ice, a crystalline solid precipitated. It was eparated by filtration and dried to give 3.6 g. of

he product decomposed at 180 C. after browning slightat 165-168 C.

Analysis.-Calcd. for C H ;,Ag B P C, 70.7; H, .5; Ag, 8.8; B, 4.9. Found: C, 68.8; H, 5.4; Ag, 8.2; i, 4.8.

he infrared absorption spectrum of the product (KBr rafer) showed one sharp band at 2550 cm.- (terminal .ydrogen).

An additional 4.0 g. of product was obtained when the iother liquor was concentrated to about one-half of its riginal volume. Its infrared absorption spectrum and ielting behavior were identical with those of the first frac- By employing the procedure set forth in the foregoing xamples, all the compounds of this invention can be preared.

The compounds of this invention are useful in the depsition of metal films on a substrate surface. For example,

glass vessel containing a solution of about 0.05 g. of

(C H P] AuB H in 5 ml. of dimethyl sulfoxide was varmed gently to about 100 C. A thin film of metallic ;old was deposited on the wall of the vessel that was in ontact with the solution.

The foregoing detailed description has been given for learness of understanding only and no unnecessary imitations are to be understood therefrom. The invention not limited to the exact details shown and described, or obvious modifications will occur to those skilled in he art.

The embodiments of the invention in which an exlusive property or privilege is claimed are defined as ollows:

, '4 1. Compounds represented by the formula selected from those of the class consisting of References Cited The following references, cited by the Examiner, are of record in the patented file of this patent or the original patent.

and

UNITED STATES PATENTS 3,217,023 11/1965 Miller 260430 X 3,296,260 3/1967 Knoth 260430 X 3,328,422 6/1967 Knoth 260430 X 3,418,346 12/1968 Parshall 260429 OTHER REFERENCES Cariati et al.: Gazz, Chim. Ital., vol. 95, pp. 3-5 (1965).

Davidson- Chem. & Ind., pp. 2021-22 (1964). Cariati et al.: Gazz, Chim. Ital., vol. 95, pp. 201-205 (1965).

TOBIAS E. LEVOW, Primary Examiner H. M. S. SNEED, Assistant Examiner US. Cl. X.R. 

